I would say it would be easier with the Z4 to burn through the paint on the edges that other cars. Ive got a paint gauge and have readings of 0.070mm in some areas where i was pretty careful.
A rotary does the same as a DA only faster, from my limited experience a rotary can easily leave holograms due to lack of work time if your not careful, where as a DA wont as you need to work it harder for longer to get the correction.
If i can get a test car around mine later today (Mates) ill do a DA v Rotary review regarding size, weight, cost, work time and ultimate final results. Dont hold your breath though lol
Cheers
PaulN